Clint Eastwood’s masterful, controversial new movie, “American Sniper,” is generating a useful debate that, at heart, is about wolves, sheep and sheepdogs.

Visually dynamic with a taut plot line, Eastwood’s film takes the audience straight into the horrific, intimate details of modern war by telling the fact-based story of Chris Kyle, the most prolific sniper in U.S. military history. We see the chaos and violence that surrounded him during four tours of duty in the Iraq war and his increasing alienation from the happy family life to which he intermittently returned throughout all his years at war.

Somewhat unexpectedly, the movie is a huge hit and a major contender in the Oscar race. It is especially popular among conservatives who see it as a bold celebration of muscular patriotism. Some antiwar liberals, on the other hand, are disturbed by what they perceive as a glorification of a war that should never have been fought.

Leftie filmmaker Michael Moore outraged conservatives when, in a tweet, he noted that his uncle was killed by a sniper in World War II. “Snipers aren’t heroes,” he wrote, “And invaders r worse.” An uproar ensued, led by a tweet from former Speaker of the House Newt Gingrich, who suggested that Moore “spend a few weeks with ISIS and Boko Haram.” The brouhaha compelled Moore to offer a fuller assessment of the film, which he mostly praised, noting that “there is also anti-war sentiment expressed in the movie.”

Conservative fans of the film may have overlooked that antiwar element. They may have also not heard that Jane Fonda -- “Hanoi Jane” -- has gone on Twitter to favorably compare “American Sniper” to her own lauded Vietnam War-era antiwar movie, “Coming Home.” She ends her tweet with “Bravo Clint Eastwood.”

David Horsey / Los Angeles Times

David Horsey / Los Angeles Times

Having seen the movie myself, I would contend that “American Sniper” is neither pro-war nor antiwar; it is simply the reality of an asymmetrical conflict reproduced as precisely as art will allow from the tight perspective of the American soldiers who are fighting in it and the families at home who pay a big price for having their loved ones repeatedly sent into battle.

Some critics argue that the film’s tight perspective is precisely the problem. In their view, leaving out the deception and political hubris that led to the American invasion, as well as the complex history of exploitation and colonialism in the Mideast, makes the movie a simplistic story of good Americans shooting at bad Muslims. I understand the point, but I also believe that there is room for a movie that does not hammer the audience with a message and, instead, with a textured portrayal, gives them a lot to ponder.

For me, I’ve found a lot to think about in the central theme of the movie, which was also the motivating principle of Chris Kyle’s life. In an early scene, an actor portraying Kyle’s father tells his sons that the world consists of wolves, sheep and the sheepdogs that protect the sheep from the wolves. That becomes Kyle’s mission and, in the end, after all the carnage, the only regret Kyle expresses is that he could not save even more of the soldiers he was assigned to protect.

The simple formulation about wolves, sheep and sheepdogs is one of the things conservatives especially love about “American Sniper.” They are always the quickest to declare that our armed forces, filled with men like Chris Kyle, are the only ones standing between all of us at home and the barbarians who would destroy our freedoms. We are the sheep, they are the sheepdogs and the killers of Islamic State, Al Qaeda, Boko Haram and their ilk are the vicious wolves. As glad as I am that the United States has the best sheepdogs in the world, though, the picture is incomplete. There are also shepherds.

Good shepherds can see the broader landscape. They can understand what might be going on beyond the horizon to make the wolves so ravenous. They can make a wise judgment about when to hold the sheepdogs in check, when to turn them loose and when to call them back. Bad shepherds, though, read the landscape wrong and depend on the sheepdogs to save them from their mistakes.

“American Sniper” is a well-told story about the sheepdogs -- the tiny percentage of Americans who volunteer to fight and die to advance the objectives of U.S. foreign policy.

In the background are the sheep; the vast majority of us who go on with our lives, risking nothing, protesting little, with only a vague appreciation of what these soldiers are doing, for good or ill, on our behalf.

And then there are the shepherds; too many of them quick to deploy and use up the sheepdogs without looking over the horizon and finding a better, more permanent way to protect the flock and give the sheepdogs a rest.